John L. Castello

JOHN L. CASTELLO has been Chairman, President and Chief Executive
Officer of XOMA Ltd. since 1992. From 1986 to 1991 he was with the Ares-
Serono Group, first as President of the Worldwide Diagnostics Division
and then as President and Chief Operating Officer of the Worldwide
Group. During his tenure as President, the group’s actual sales
increased from $300 million to $750 million. From 1977 to 1986, he was
with Amersham International, rising to the post of Chief Executive of
the worldwide medical divisions. Previously, he worked for Abbott
Laboratories and General Foods in a progression of management positions.
Mr. Castello holds a BS degree in Mechanical/Industrial Engineering from
Notre Dame University.